The intermolecular cyclization of diethanolamine and methylamine has been carried out over copper-chromite, zinc-chromite, Cu-Al2O3 and Ni-SiO2 catalysts in the temperature range from 250 to 350-degrees-C and 80 atm. hydrogen pressure leading to N-methylpiperazine. The selectivity of N-methylpiperazine is higher (> 95%) at a conversion of > 75% for copper-chromite and Cu-Al2O3 in comparison to that of Ni-SiO2 catalyst.